The mobile Internet is an industry developed fastest, having a greatest market potential and a most attractive prospect in the present world. Wireless access is a core technology in the mobile Internet industry. At present, multiple advanced Radio Access Technologies (RATs) (Multiple RAT: Multi-RAT) coexist, so that a user terminal may access a wireless network at a high speed and enjoy high-quality service. Typical technologies include a wireless wide area network access technology represented by Long Term Evolution (LTE) and a Wireless Local Area Network (WLAN) technology represented by Institute of Electrical and Electronic Engineers (IEEE) 802.11. A WLAN is a network constructed with a wireless communication technology within a certain local range, an architecture diagram of which is shown in FIG. 1. Compared with LTE, a WLAN is small in coverage, high in access rate and low in using cost.
As a typical representative of a 3rd Generation Partnership Project (3GPP) wireless communication family network, an LTE network is formed by an Evolved NodeB (eNB) of an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC). The network is flattened. The E-UTRAN includes a set of eNBs connected with the EPC through an S1 interface, and the eNBs may be connected with one another through X2. S1 and X2 are logical interfaces. An EPC may manage one or more eNBs, A NodeB may also be controlled by multiple EPCs. An eNB may manage one or more cells. An LTE-Advance (LTE-A) system is evolved from an LTE system with a network architecture consistent with LTE. LTE is a 4th-Generation (4G) technology. Compared with 3rd-Generation (3G), LTE has technical advantages in multiple aspects of a higher data rate, low-delay transmission and guaranteed Quality of Service (QoS). Compared with a WLAN, LTE has wider coverage, and supports high-speed movement and roaming of a user terminal.
Along with constant evolution of a communication network in the future, coexistence of network modes of multiple systems is an inevitable trend, including fusion networking of 2nd-Generation (2G), 3G and LTE, 3GPP-WLAN fusion networking or the like. For example, an LTE-WLAN fusion networking diagram is shown in FIG. 2. Due to complementary properties of a WLAN and a 3GPP wireless communication family network, 3GPP-WLAN interconnection and intercommunication become one of hot issues for equipment manufacturers, system integrators, operating companies and scientific research institutions. The basic principle is to reduce influence on existing standards and systems of the WLAN and the 3GPP as much as possible. That is, the WLAN standard is kept unchanged, and an existing 3GPP specification is minimally modified. A key for intercommunication and integrated structure design of the 3GPP and the WLAN is to provide an interaction function between the 3GPP and the WLAN on the basis of an IEEE 802.11 standard.